“I am proud to endorse Chris Murphy for the United States Senate and join his team,” Tong said in a statement released by the Murphy campaign. “I’ve learned a lot about Chris in this campaign. We are both sons of Connecticut who love our home state.”

That leaves former Secretary of State Susan Bysiewicz, and other less credible candidates, in a fight with Murphy for the Democratic nod. The primary is August 14.

Former World Wrestling Entertainment CEO Linda McMahon and former Rep. Christopher Shays (R) are the top candidates battling for the GOP nomination.